# T.H. Tahirov
**Tahir H. Tahirov** is a structural biologist who works on the molecular machines of [DNA replication](https://www.edgepedia.org/dna-replication) and transcription. He holds the Warren and Agnes Ritchie Professorship in Cancer Research at the [University of Nebraska Medical Center](https://www.edgepedia.org/university-of-nebraska-medical-center) (UNMC) Eppley Institute for Research in Cancer and Allied Diseases, where he has been Coordinator of Chromatin Structural Biology Research since 2016, and he is a full member of the Fred & Pamela Buffett Cancer Center.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) He is known for crystal structures of transcription factor complexes bound to DNA, including the AML1/Runx1 Runt domain with CBFβ and the cooperative c-Myb–C/EBPβ system, and for the structure of HIV-1 Tat bound to the human elongation factor P-TEFb.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html)
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| **Position** | Warren and Agnes Ritchie Professor in Cancer Research and Coordinator of Chromatin Structural Biology Research, UNMC Eppley Institute, since 2016[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) |
| **Field** | Structural biology of DNA replication and transcription; biophysics and biochemistry[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) |
| **Training** | M.S. in Metallophysics, Kiev Polytechnic Institute, 1984; Ph.D. in Physical Chemistry, Rostov State University, 1989[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) |
| **Signature work** | "Structural Analyses of DNA Recognition by the AML1/Runx-1 Runt Domain and Its Allosteric Control by CBFβ", *Cell*, 2001[2](https://pubmed.ncbi.nlm.nih.gov/11257229/) |
| **Virus work** | Crystal structure of HIV-1 Tat complexed with human P-TEFb, *Nature*, 2010[3](https://doi.org/10.1038/nature09131) |
| **Current focus** | Human DNA replication machines, herpesvirus DNA replication, and structure-based drug design[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) |
| **Funding** | NIH grant R35GM152032, "DNA Replication Machines: Structure-Function Studies"[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) |
## Education and career
Tahirov earned an M.S. in Metallophysics from Kiev Polytechnic Institute in Ukraine in 1984 and a Ph.D. in Physical Chemistry from Rostov State University in Russia in 1989.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html)
In 1996 he received an Institute for Protein Research, Osaka University Center of Excellence Postdoctoral Fellowship Award.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) Since 2016 he has combined the Ritchie Professorship with coordination of chromatin structural biology research at the institute.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html)
His honors include the 2007 Gordon Bell Prize, for "A 281 Tflops Calculation for X-ray Protein Structure Analysis with the Special-Purpose Computer MDGRAPE-3", and honorary membership in the Biophysical Society in 2004.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html)
## Representative work
The 2001 *Cell* paper "Structural Analyses of DNA Recognition by the AML1/Runx-1 Runt Domain and Its Allosteric Control by CBFβ" ([PubMed](https://pubmed.ncbi.nlm.nih.gov/11257229/)) determined crystal structures of the Runx1 (AML1) [Runt domain](https://www.edgepedia.org/runt-domain) bound to DNA, alone and in complexes with partner transcription factors, including a ternary structure with the C/EBPβ bZip dimer on a CSF1R promoter fragment solved at 3.00 Å resolution.[4](https://jenalib.leibniz-fli.de/cgi-bin/ImgLib.pl?CODE=1hjb) Its central finding concerned allostery (regulation of a protein by binding at a distant site): CBFβ binds to AML1 and enhances its DNA binding affinity by an allosteric mechanism without contacting the DNA itself.[5](https://doi.org/10.1107/s0108767302085884)
## Transcription factor cooperation on promoters
According to a 2002 *Cell* paper, c-Myb and C/EBPβ interact from distant sites on the promoter, and their cooperation is accompanied by looping of the intervening portion of DNA.[5](https://doi.org/10.1107/s0108767302085884) The crystal structures determined in this series included c-Myb(R1R2R3)–C/EBPβ(bZip)–DNA, the AMV v-Myb equivalent, and AML1(Runt)–CBFβ–C/EBPβ(bZip)–DNA complexes.[5](https://doi.org/10.1107/s0108767302085884) Protein Data Bank Japan records a C/EBPβ ternary protein–DNA complex deposited on 30 January 2001 and solved by [X-ray crystallography](https://www.edgepedia.org/x-ray-crystallography), with structures from this period published in *Nature* and in *Cell* volume 108 (2002) at resolutions such as 2.45 Å.[6](https://pdbj.org/search/pdb?d_authors=%22Tahirov%2C+T.H%22)
## HIV Tat and P-TEFb
The 2010 *Nature* paper "Crystal structure of HIV-1 Tat complexed with human P-TEFb" ([doi:10.1038/nature09131](https://doi.org/10.1038/nature09131)), published on 1 June 2010, reported high-resolution crystal structures of the Tat–P-TEFb complex and of the complex with the ATP analog AMP-PNP and magnesium ion bound.[3](https://doi.org/10.1038/nature09131) In the structure (PDB 3MI9), Tat adopts a conformation complementary to the P-TEFb surface and makes extensive contacts mainly with the cyclin T1 subunit, but also with the T-loop of the Cdk9 subunit, and it induces significant conformational changes in P-TEFb.[7](https://www.rcsb.org/structure/3MI9) Because P-TEFb is the host elongation factor HIV hijacks to drive transcription of its genome, the structure was described as laying a foundation for designing compounds that would specifically inhibit the Tat–P-TEFb complex and block HIV replication.[7](https://www.rcsb.org/structure/3MI9) The work was funded by NIAID, NIGMS, NCRR, and the [National Cancer Institute](https://www.edgepedia.org/national-cancer-institute).[3](https://doi.org/10.1038/nature09131)
## Research program at Nebraska
At the Eppley Institute, Tahirov's laboratory studies the mechanisms of human DNA replication, herpesvirus DNA replication, and virus–host interactions, with a stated aim of structure-based design of antiviral and anticancer drugs, using X-ray crystallography, and cryo-electron microscopy.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) Key results include resolving the structure of the regulatory subunits of [DNA polymerase](https://www.edgepedia.org/dna-polymerase) δ, which revealed a conserved fold across B-family polymerases, and the discovery of a polymerase switch mechanism between Pol δ and Pol ζ mediated by shared accessory subunits.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) The lab also developed a method to synthesize native-like chimeric RNA–DNA primers with 5′-triphosphates, which showed altered binding kinetics and polymerase fidelity and enabled stabilization of elongation; binding and kinetic studies at physiological salt concentrations showed increased substrate specificity and processivity differences, notably for Pol α, whose fidelity depends on the RNA/DNA primer ratio.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) The work is supported by the NIH grant R35GM152032, "DNA Replication Machines: Structure-Function Studies".[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html)
## Recent developments
Recent output concentrates on the human primosome and on herpesviruses. A 2023 *Nature Structural & Molecular Biology* paper reported structures of human primosome elongation complexes.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) In 2025, "Nsp1 stalls DNA polymerase α at DNA hairpins" appeared in *Scientific Reports* on 21 May, and "The human primosome requires replication protein A when copying DNA with inverted repeats" appeared in *Nucleic Acids Research* on 11 August.[8](https://search.lib.auth.gr/Summon/Search?lookfor=%22Tahirov%2C+Tahir+H.%22&type=Author) A bioRxiv preprint of 15 May 2025, "Structural Basis of Herpesvirus Helicase-Primase Inhibition by Pritelivir and Amenamevir", extended the antiviral structural work.[1](https://www.unmc.edu/eppley/about/faculty/tahirov.html) In November 2025, UNMC announced that a team led by Tahirov, together with a group at the University of Wisconsin, had determined the structure of the herpes simplex virus helicase-primase complex and how inhibitors affect it.[9](https://www.unmc.edu/newsroom/2025/11/14/unmc-researchers-publish-findings-on-herpes-simplex-virus/)
## References
1. [Tahir Tahirov, PhD | Eppley Institute | University of Nebraska Medical Center](https://www.unmc.edu/eppley/about/faculty/tahirov.html)
2. [Structural analyses of DNA recognition by the AML1/Runx-1 Runt domain and its allosteric control by CBFβ (Cell, 2001), PubMed](https://pubmed.ncbi.nlm.nih.gov/11257229/)
3. [Crystal structure of HIV-1 Tat complexed with human P-TEFb (Nature, 2010)](https://doi.org/10.1038/nature09131)
4. [PDB 1HJB | JenaLib](https://jenalib.leibniz-fli.de/cgi-bin/ImgLib.pl?CODE=1hjb)
5. [Structural aspects of gene expression by AML1/CBFβ, c-Myb, AMV v-Myb, C/EBPβ and Ets-1 (IUCr)](https://doi.org/10.1107/s0108767302085884)
6. [Protein Data Bank Japan, search results for Tahirov, T.H.](https://pdbj.org/search/pdb?d_authors=%22Tahirov%2C+T.H%22)
7. [RCSB PDB 3MI9: Crystal structure of HIV-1 Tat complexed with human P-TEFb](https://www.rcsb.org/structure/3MI9)
8. [Library catalog results, Tahirov, Tahir H.](https://search.lib.auth.gr/Summon/Search?lookfor=%22Tahirov%2C+Tahir+H.%22&type=Author)
9. [UNMC researchers publish findings on herpes simplex virus](https://www.unmc.edu/newsroom/2025/11/14/unmc-researchers-publish-findings-on-herpes-simplex-virus/)
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*Topic: Encyclopedia › Life and health › Life and health scientists › Life scientists › Researchers in structural biology, biochemistry, and biophysics › Nucleic acids, RNA, and chromatin › DNA replication, repair, and metabolism*
*Initially written Sep 21, 2026 · Reviewed: Sep 25, 2026 · Edited: Sep 25, 2026; Oct 11, 2026; Oct 15, 2026 · Last review: Sep 25, 2026*
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